Liquid crystal display device

ABSTRACT

The present invention provides a liquid crystal display device which can obviate the generation of leaking of light and display irregularities in the vicinities of so-called dummy pixels. The liquid crystal display device includes a pair of substrates which are arranged to face each other in an opposed manner with liquid crystal sandwiched therebetween, a plurality of gate signal lines and a plurality of drain signal lines which are formed on one substrate in a matrix array, a plurality of pixel regions defined by the gate signal lines and the drain signal lines, and a reference electrode and a pixel electrode which are formed in the inside of each pixel region. In such a constitution, the plurality of pixel regions are formed in both a display region and a non-display region, and a voltage applied to the reference electrodes is applied to the pixel electrodes in the inside of the pixel regions in the non-display region.

The present application claims priority from Japanese applicationJP2006-192274 filed on Jul. 13, 2006, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

The present invention relates to a liquid crystal display device, andmore particularly to a liquid crystal display device which includesnon-display pixels which are called dummy pixels in general.

In a liquid crystal display device, a large number of pixels are formedon liquid-crystal-side surfaces of respective substrates which arearranged to face each other in an opposed manner with liquid crystalsandwiched therebetween, and a liquid crystal display part (liquidcrystal display region) is formed by a mass of these pixels.

Each pixel is, for example, constituted of a switching element (thinfilm transistor) which is formed in a region surrounded by gate signallines which extend in the x direction and are arranged in parallel inthe y direction and drain signal lines which extend in the y directionand are arranged in parallel in the x direction and is turned on inresponse to a gate signal from the gate signal line, a pixel electrodeto which a video signal line is supplied from the drain signal line viathe turned-on switching element, and a reference electrode whichgenerates an electric field between the reference electrode and thepixel electrode.

In performing the display driving in a liquid crystal display parthaving such pixels, pixel rows which are formed along the respectivegate signal lines are sequentially selected by sequentially supplying(scanning) gate signals to the respective gate signal lines, and videosignals are supplied to the respective pixels of the selected pixel rowvia each drain signal line in conformity with such timing. In this case,each pixel to which the video signal is supplied is configured to hold avoltage corresponding to the video signal in the pixel electrode due toa capacitive element or parasitic capacitance stored in the pixel untilthe next signal is supplied.

However, in such a constitution, the difference in a capacitance value,the disturbance of the orientation of the liquid crystal or the like isgenerated in respective pixels in an uppermost pixel row or a lowermostpixel row and hence, there appears a phenomenon in which the displaydiffers from a display of another pixel.

Here, there has been known a technique which covers the respectivepixels in the uppermost pixel row and the lowermost pixel row with alight blocking film thus constituting these respective pixels as dummypixels which do not contribute to the display.

The detail of the dummy pixels is disclosed in the following

Patent Document 1 or Patent Document 2, for example. Patent Document 1:JP-A-2005-241778 (corresponding US application; US2005/0184980A1) PatentDocument 2: JP-A-11-52427 SUMMARY OF THE INVENTION

However, the liquid crystal display device having such aconstitutionisconfigured such that, for example, as described in Patent Document 1,the dummy pixels are driven in the same manner as other pixels whichcontribute to the display so as to repeat the transmission and theblocking of light. Accordingly, even when the dummy pixels are coveredwith the light blocking film, there exists a drawback that leaking oflight is generated from an end periphery of the light blocking film.

On the other hand, in Patent Document 2, the dummy pixels are configuredto be separated from gate signal lines and drain signal lines thuspreventing the transmission and blocking of light.

However, the dummy pixels described in Patent Document 2 has a potentialthereof always held in a unstable state and hence, impurities in theinside of liquid crystal in the vicinity of the dummy pixels are liableto be easily attracted to this potential unstable portion thus givingrise to a phenomenon that display irregularities are generated in thevicinity of the dummy pixels.

It is an object of the present invention to provide a liquid crystaldisplay device which can obviate the generation of leaking of light anddisplay irregularities in the vicinity of so-called dummy pixels(non-display pixels).

To simply explain the summary of typical inventions among inventionsdisclosed in this specification, they are as follows.

A liquid crystal display device of the present invention includes: apair of substrates which are arranged to face each other in an opposedmanner with liquid crystal sandwiched therebetween; a plurality of gatesignal lines and a plurality of drain signal lines which are formed onone substrate in a matrix array; a plurality of pixel regions defined bythe gate signal lines and the drain signal lines; and a referenceelectrode and a pixel electrode which are formed in the inside of eachpixel region, wherein the plurality of pixel regions are formed in botha display region and a non-display region, and a voltage applied to thereference electrodes is applied to the pixel electrodes in the inside ofthe pixel regions in the non-display region.

That is, the liquid crystal display device of the present invention isconfigured such that, in the dummy pixel, by applying the same voltageto the pixel electrode and the reference electrode, driving of liquidcrystal of the dummy pixel is not performed.

Here, the present invention is not limited to the above-mentionedconstitution and various modifications are conceivable without departingfrom a technical concept of the present invention.

The liquid crystal display device having such a constitution can obviatethe generation of leaking of light and display irregularities in thevicinity of the so-called dummy pixels (non-display pixels).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a view showing one embodiment of a liquid crystal displaydevice according to the present invention, and also is a plan viewshowing respective pixels which are arranged in the vicinity of aperipheral portion of a black matrix;

FIG. 2 is a schematic constitutional view showing one embodiment of theliquid crystal display device according to the present invention;

FIG. 3A is a view showing one embodiment of the liquid crystal displaydevice according to the present invention, and FIG. 3B is a view showingthe constitution around the black matrix;

FIG. 4 is a plan view of the black matrix which is used in oneembodiment of the liquid crystal display device according to the presentinvention;

FIG. 5 is a view showing one embodiment of the liquid crystal displaydevice according to the present invention, and also is a plan viewshowing respective pixels which are arranged in an liquid crystaldisplay region; and

FIG. 6A is a cross-sectional view taken along a line VI(a)-VI(a) in FIG.1, and FIG. 6B is a cross-sectional view taken along a line VI(b)-VI(b)in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, embodiments of the liquid crystal display device accordingto the present invention are explained in conjunction with the drawings.

FIG. 2 is a schematic constitutional view showing one embodiment of theliquid crystal display device according to the present invention.

In FIG. 2, substrates 1, 2 are arranged to face each other in an opposedmanner with liquid crystal sandwiched therebetween. For example, boththe respective substrates 1, 2 are constituted of a transparentsubstrate made of glass or the like. The substrate 2 is formed with anarea slightly smaller than an area of the substrate 1, and has a regionwhere the substrate 1 is exposed from the substrate 2, for example, on aleft side and an upper side of the substrate 1 in the drawing. Gatesignal driving circuits GD each constituted of a semiconductor chip aremounted on the region arranged on the left side of the substrate 1 inthe drawing and drain signal driving circuits DD each constituted of asemiconductor chip are mounted on the region arranged on an upper sideof the substrate 1 in the drawing.

The substrate 2 is fixed to the substrate 1 using a sealing agent SLwhich is formed on the whole area of a periphery of the substrate 2, andthe sealing agent SL has a function as a sealing agent which sealsliquid crystal interposed between the respective substrates 1, 2.

A region which is surrounded by the sealing agent SL and forms a regionin which openings of a black matrix (light blocking film) BM are formedis constituted as a liquid crystal display region AR.

The liquid crystal display region AR is constituted of a mass of a largenumber of pixels which are arranged in a matrix array. The constitutionof each pixel is, in FIG. 2, shown by an equivalent circuit in anenlarged view A′ of a dotted circular frame A in the inside of theliquid crystal display region AR.

That is, as shown in the enlarged view A′, gate signal lines GL andcommon signal lines CL which, in the drawing, extend in the x directionand are arranged in parallel in the y direction are formed, and drainsignal lines DL which, in the drawing, extend in the y direction and arearranged in parallel in the x direction are formed.

Further, the gate signal lines GL and the common signal lines CL arealternately arranged, for example, from an upper side of the drawing toa lower side, in order of the gate signal line GL, the common signalline CL which is spaced apart from the gate signal line GL with arelatively large distance therebetween, the gate signal line GL which isspaced apart from the common signal line CL with a relatively smalldistance therebetween, the common signal line CL which is spaced apartfrom the gate signal line GL with a relatively large distance, . . . .

A region which is surrounded by the gate signal line GL, the commonsignal line CL which is spaced apart from the gate signal line GL withthe relatively large distance, and a pair of drain signal lines DL isconstituted as a pixel region.

The pixel region includes a thin film transistor TFT which is turned onin response to a gate signal from the gate signal line GL, a pixelelectrode PX to which a video signal from the drain signal line DL issupplied via the thin film transistor TFT which is turned on, and areference electrode CT (It is also called a common electrode CT.) whichgenerates an electric field between the reference electrode CT and thepixel electrode PX and is connected to the common signal line CL.

Between the pixel electrode PX and the reference electrode CT, forexample, the electric field which is substantially parallel to surfacesof the substrates 1, 2 is generated, and the behavior of molecules ofthe liquid crystal is generated due to the electric field.

Here, the respective gate signal lines GLget overa forming region of thesealing agent SL on the left side of the drawing, for example, and areconnected to output bumps of the gate signal driving circuits GD.Further, the respective common signal lines CL get over the formingregion of the sealing agent SL on the right side of the drawing, forexample, and are connected to a common signal terminal CTM. Further, therespective drain signal lines DL get over the forming region of thesealing agent SLontheuppersideofthedrawing, for example, andareconnectedto output bumps of the drain signal driving circuits DD.

The gate signal driving circuits GD select a pixel row, for example, bysequentially supplying (scanning) gate signals to the respective gatesignal lines GL, and the drain signal driving circuits DD supply videosignals to the respective pixels of the selected pixel row via therespective drain signal lines DL.

FIG. 3 is a view showing an upper left portion of the liquid crystaldisplay region AR of the liquid crystal display device, that is, aportion of a dotted line rectangular frame B shown in FIG. 2 in anenlarged manner. However, the gate signal driving circuits GD, the gatesignal lines GL, the drain signal driving circuits DD, the drain signallines DL and the like are omitted from the drawing.

In FIG. 3A, the substrate 2 has a periphery thereof fixed to thesubstrate 1 by way of the sealing agent SL.

Here, the black matrix BM is formed on a liquid-crystal-side surface ofthe substrate 2. To be more accurate, the black matrix BM is, as shownin FIG. 4, formed in a pattern in which openings HL are formed in theliquid crystal display region AR at portions which face center portionsof the respective pixels excluding peripheries of the respective pixels.However, in FIG. 3A, for the sake of brevity, only a peripheral portionof the black matrix BM having a width W where the openings HL are notformed (also referred to as a peripheral portion of black matrix BM) isshown.

Further, FIG. 3B shows a cross-section taken along a line b-b in FIG.3A. In FIG. 3B, respective pixels PIX are formed on aliquid-crystal-LC-side surface of the substrate 1 which faces thesubstrate 2 in an opposed manner, and these pixels PIX are constitutedof pixels PIX(R) which contribute to an actual display and so-calleddummy pixels PIX(D).

The dummy pixels PIX(D) are formed, in this embodiment, as a group ofpixels of one row, for example, which is formed on an upper stage of therespective pixels PIX(R) which are arranged in a matrix array andcontributes to the display in parallel to the gate signal line GL, and agroup of pixels of one row, for example, which is formed on a lowerstage of the respective pixels PIX(R) in parallel to the gate signalline GL.

These dummy pixels PIX(D) are positioned and arranged below a peripheralportion of the black matrix BM, and the openings HL are not formed inthe peripheral portion of the black matrix BM and hence, a viewer of theliquid crystal display device cannot observe the dummy pixels PIX(D)with naked eyes.

Although the constitution of the dummy pixels PIX(D) is explained indetail later, because of necessity to give the same conditions to thedummy pixels PIX(D) with respect to a capacitance (including parasiticcapacitance) and a shape of surface undulation which influences theorientation of the liquid crystal which the pixels PIX (R) whichcontribute to the display possess, it is desirable that the dummy pixelsPIX(D) have the substantially equal constitution as the pixels PIX(R).

FIG. 5 is a plan view showing one embodiment of the pixels PIX(R) whichcontribute to the display, wherein FIG. 5 shows (2×3) pieces of pixelsPIX(R), for example. Further, FIG. 6B is a cross-sectional view takenalong a line VI(b)-VI(b) in FIG. 5.

First of all, on the liquid crystal-surface side of the substrate 1, thegate signal lines GL and the common signal lines CL are formed. Forexample, the gate signal line GL is formed on an upper side in thedrawing with respect to the pixel region, and the common signal line CLis formed on a lower side with respect to the pixel region. Due to thegate signal line GL, the common signal line CL and the drain signal lineDL described later, the pixel region is defined from another neighboringpixel region.

The reference electrode CT is formed in the pixel region between thegate signal line GL and the common signal line CL, and the referenceelectrode CT is electrically connected with the common signal line CL ina state that the reference electrode CT directly overlaps the commonsignal line CL.

The reference electrode CT is formed of a planar electrode which isformed on a center portion of the pixel region excluding slightperipheral portions and, at the same time, is constituted as atransparent electrode formed of an ITO (Indium Tin Oxide) film, forexample.

On the surface of the substrate 1 on which the gate signal lines GL, thecommon signal lines CL and the reference electrodes CT are formed inthis manner, a first insulation film IN1 is formed in a state that thefirst insulation film IN1 also covers these gate signal lines GL, commonsignal lines CL and reference electrodes CT. The first insulation filmIN1 is, for example, formed of a silicon nitride film, and functions asa gate insulation film in a region where a thin film transistor TFTdescribed later is formed.

Then, on an upper surface of the first insulation film IN1,semiconductor layers SC are formed in a state that the semiconductorlayer SC overlaps a portion of the gate signal line GL. Further, on asurface of the semiconductor layer SC, the drain electrode DT and asource electrode ST are formed in a spaced-apart manner from each otherthus forming an MIS-type transistor (thin film transistor TFT) havingthe inverse staggered structure which uses the portion of the gatesignal line GL as the gate electrode.

Here, for example, the drain electrode DT is integrally formed with thedrain signal line DL and, at the same time, the source electrode ST isformed simultaneously with the drain electrode DT. The source electrodeST extends to the outside of the region where the semiconductor SC isformed, and the source electrode ST is connected with the pixelelectrode PX described later at an extended portion thereof.

Here, in the thin film transistor TFT, the drain electrode DT and thesource electrode ST have properties which are exchanged depending on themanner of applying a bias. In this specification, a side which isconnected to the drain signal line DL is referred to as the drainelectrode DT and a side which is connected to the pixel electrode PX isreferred to as the source electrode ST.

Here, the drain electrodes DT, drain signal lines DL and the sourceelectrodes ST are formed on an upper surface of a second insulation filmIN2 which is formed on the surface of the substrate 1 in a state thatthe second insulation film IN2 also covers the semiconductor layer SC,and the drain electrode DT and the source electrode ST are electricallyconnected with the semiconductor layer SC via through holes formed inthe second insulation film IN2. Here, the second insulation film IN2functions as a protective film which prevents a direct contact of liquidcrystal with the thin film transistor TFT.

Further, on an upper surface of the second insulation film IN2, thepixel electrodes PX are formed in a state that the pixel electrodes PXoverlap the reference electrodes CT. The pixel electrodes PX are formedin a pattern in which strip-like electrodes extend in one direction andare arranged in parallel in the direction which intersects onedirection, and respective electrodes have both ends thereof connectedwith each other, for example. The pixel electrodes PX are constituted ofa transparent electrode formed of an ITO (Indium Tin Oxide) film, forexample.

When the voltage difference is generated between the reference electrodeCT and the pixel electrodes PX, an electric field corresponding to thevoltage difference is generated substantially parallel to the surface ofthe substrate 2, and the behavior of the molecules of the liquid crystalis generated by the electric field.

Here, although not shown in the drawing, an orientation film is formedon the surface of the substrate 1 on which the pixel electrodes PX areformed. The orientation film is directly brought into contact withliquid crystal thus determining the initial orientation direction of theliquid crystal.

Further, the black matrix BM which is formed on theliquid-crystal-surface side of the substrate 2 which faces therespective pixels shown in FIG. 5 in an opposed manner covers the gatesignal lines GL, the drain signal line DL, the thin film transistor TFTand the like, and forms openings which expose the center portions of thepixels. The openings are indicated by symbols HL in FIG. 5.

FIG. 1 is a plan view showing one embodiment of pixels PIX(D) which arereferred to as dummy pixels. In FIG. 1, the dummy pixels PIX(D) aredepicted together with the above-mentioned pixel PIX(R) in a state thatthe dummy pixels PIX(D) are arranged close to the dummy pixels PIX(R).

That is, in FIG. 1, a dotted line portion X-X which defines a liquidcrystal display region AR and a peripheral portion of the black matrixBM is shown. Using this dotted line portion X-X as a boundary, thepixels PIX(D) which are referred to as the dummy pixel are formed on aperipheral-portion side of the black matrix BM, while the pixels PIX(R)which contribute to a display is formed on aliquid-crystal-display-region-AR side. FIG. 6A is a cross-sectional viewtaken along a line VI (a)-VI (a) in FIG. 1.

The pixel PIX(D) is formed in a region which is surrounded by the linelayer LL, the common signal line CL and the drain signal lines DL formedon an upper surface of the substrate 1 as described later.

The line layers LL correspond to the gate signal lines GL of the pixelsPIX (R) which contribute to the display, wherein the line layers LL areformed in the substantially same pattern as the gate signal lines GL atportions corresponding to the gate signal lines GL. The reason that theline layers LL are not referred to as the gate signal lines GL is thatthe line layers LL are configured such that the reference voltage isapplied to the line layers LL instead of a gate signal.

Further, in the same manner as the common signal lines CL of the pixelsPIX(R) which contribute to the display, the reference voltage is appliedto the common signal lines CL.

Over a surface of the substrate 1 on which the line layers LL and thecommon signal lines CL are formed, a first insulation film IN1 is formedin a state that the first insulation film IN1 also covers the linelayers LL and the common signal lines CL. The first insulation film IN1is formed by extending the first insulation film IN1 formed on thepixels PIX(R) which contribute to the display extends to a region of thepixels PIX(D).

Here, the pixel PIX(D) is configured such that the thin film transistorTFT formed in the pixel PIX (R) which contributes to the display is notformed in the pixel PIX(D). This is because that, as described later,the pixel PIX(D) is configured not to drive the liquid crystal andhence, the pixel PIX(D) is not required to form the thin film transistorTFT therein.

Further, in this embodiment, a position in the pixel PIX(D) whichcorresponds to a portion where the thin film transistor TFT of the pixelPIX(R) which contributes to the display is formed is spaced apart fromthe liquid crystal display region AR with a large distance therebetween.Accordingly, it is considered that the disturbance of orientation on thesurface of the pixel due to the non-formation of the thin filmtransistor TFT in the pixel PIX(D) does not influence the liquid crystaldisplay region AR.

A second insulation film IN2 is formed on the upper surface of the firstinsulation film IN1. The second insulation film IN2 is formed byextending the second insulation film IN2 formed on the pixels PIX(R)which contribute to the display to the region of the pixels PIX(D).

Further, on the second insulation film IN2, electrodes PX′ are formed ina state that the electrodes PX′ overlap the reference electrode CT. Theelectrodes PX′ are formed on the same layer as the pixel electrodes PXat the pixels PIX(R) which contribute to the display in the same patternas the pixel electrodes PX. Different from the pixel electrodes PX, thevideo signal is not supplied to this electrodes PX′, and the referencevoltage is applied to the electrodes PX′.

That is, the electrodes PX′ are integrally formed with a referencevoltage supply signal line CVL which is formed such that the referencevoltage supply signal line CVL strides over the line layer LL and ispulled out in the direction away from the liquid crystal display regionAR. The reference voltage is supplied to the electrodes PX′ by way ofthe reference voltage supply signal line CVL.

Due to such a constitution, the reference voltage is applied to theelectrode PX′ and the reference electrode CT which are arranged in thepixel PIX(D) respectively and hence, the behavior of the liquid crystalis not generated thus eliminating a possibility of the repetition oftransmission of light and the blocking of light.

Accordingly, there is no possibility that leaking of light is generatedfrom end peripheries of the black matrix BM. Further, the pixel PIX(D)has a potential thereof always held in a stable state and hence, it ispossible to obviate a phenomenon that impurities in the inside of theliquid crystal in the vicinity of the pixel PIX(D) is attracted wherebythe generation of display irregularities can be prevented.

Further, out of the periphery outside the liquid crystal display regionAR, at a portion which is arranged parallel to the drain signal line DL,the reference voltage supply signal line CVL is formed parallel to thedrain signal line DL.

The reference voltage supply signal line CVL is formed with a large linewidth along with the reference voltage supply signal line CVL which isdirectly pulled out from the electrode PX′ of the pixel PIX(D). With theuse of these reference voltage supply signal lines CVL, a relativelylarge region which surrounds the whole periphery outside the liquidcrystal display region AR and the region where the pixels PIX(D)referred to as dummy electrodes are formed. Due to such a constitution,the infiltration of noises can be avoided thus allowing the respectivepixels PIX(R) in the liquid crystal display region AR to perform thestable operation.

Here, FIG. 1 shows the constitution of the pixels PIX(D) for dummydisplay which are arranged on an uppermost stage side of the liquidcrystal display region AR. However, the pixels PIX(D) for dummy displaywhich are also arranged on a lowermost stage side of the liquid crystaldisplay region AR, and pixel PIX(D) for dummy display also has aconstitution substantially equal to the constitution shown in FIG. 1.

The above-mentioned liquid crystal display device is configured suchthat in each pixel PIX(R) which contributes to the display, the electricfield parallel to the substrate 1 is generated between the referenceelectrode CT and the pixel electrode PX and the behavior of the liquidcrystal molecules is generated by the electric field.

Compared to a liquid crystal display device which is configured toarrange electrodes on respective opposedly-facing surfaces of therespective substrates arranged with liquid crystal sandwichedtherebetween and an electric field is generated between theseelectrodes, this liquid crystal display device uses a relatively weakelectric field. Due to such a relatively weak electric field, the pixelelectrode PX is arranged at a position extremely close to the referenceelectrode CT.

This implies that even when the dummy pixels are arranged close to thepixels which contribute to the display, and in the dummy pixels, avoltage having the same potential as the voltage applied to thereference electrode CT is supplied to the respective electrodescorresponding to the reference electrode CT and the pixel electrodes PX,there is no possibility that the electric field generated in the pixelswhich contribute to the display is attracted to the dummy pixel side.

Accordingly, even when the dummy pixels have the above-mentionedconstitution, there is no possibility that the distribution of theelectric field is disturbed in the pixels which contribute to thedisplay and are arranged close to the dummy pixels.

Further, in the above-mentioned embodiment, dummy pixels are formed suchthat one row of the dummy pixels is formed on the upper stage of theliquid crystal display region and one row of dummy pixels is formed onthe lower stage of the liquid crystal display region. However, it isneedless to say that the present invention is not limited to suchembodiments, and a plurality of rows of dummy pixels may be formed onthe upper and lower stages of the liquid crystal display regionrespectively.

The above-mentioned respective embodiments are used in a single form orin combination. This is because that the advantageous effects can beobtained singularly or synergistically.

1. A liquid crystal display device comprising: a pair of substrateswhich are arranged to face each other in an opposed manner with liquidcrystal sandwiched therebetween; a plurality of gate signal lines and aplurality of drain signal lines which are formed on one substrate in amatrix array; a plurality of pixel regions defined by the gate signallines and the drain signal lines; and a reference electrode and a pixelelectrode which are formed in the inside of each pixel region, whereinthe plurality of pixel regions are formed in both a display region and anon-display region, and a voltage applied to the reference electrodes isapplied to the pixel electrodes in the inside of the pixel regions inthe non-display region.
 2. A liquid crystal display device according toclaim 1, wherein non-display region lines which are arranged in parallelwith the gate signal lines are formed in the inside of the non-displayregion at positions where the non-display region lines do not overlapthe reference electrodes, and a voltage applied to the referenceelectrodes is applied to the non-display region lines.
 3. A liquidcrystal display device according to claim 1, wherein the non-displayregion lines are formed on the same layer as the gate signal lines.
 4. Aliquid crystal display device according to claim 1, wherein commonsignal lines to each of which the reference electrodes in the respectivepixel regions which are arranged in the row direction are connected incommon are formed in the pixel regions of the display region and thenon-display region, and the common signal lines in the display regionand the non-display region are formed on the same layer in the samepattern.
 5. A liquid crystal display device according to claim 1,wherein the pixel regions in the inside of the display region includethin film transistors which are operated in response to a gate signalfrom the gate signal lines and a video signal from the drain signallines is supplied to the pixel electrodes in response to the operationof the thin film transistors, and the pixel regions in the inside of thenon-display region do not include the thin film transistors.
 6. A liquidcrystal display device according to claim 1, wherein reference voltagesupply signal lines for applying the reference voltage to the pixelelectrode in the pixel regions in the inside of the non-display regionare formed in the inside of the non-display region, and the referencevoltage supply signal lines are formed in parallel to the drain signallines.
 7. A liquid crystal display device according to claim 6, whereina line width of the reference voltage supply signal lines is larger thana line width of the drain lines.
 8. A liquid crystal display deviceaccording to claim 7, wherein the reference electrode has a rectangularshape.
 9. A liquid crystal display device according to claim 8, whereinthe line width of the reference voltage supply signal lines issubstantially equal to a width of the reference electrodes.
 10. A liquidcrystal display device according to claim 1, wherein light-blockingfilms are formed at positions which overlap the pixel regions of thenon-display region.